Poster H1 - Anti-Platelet Drug Ifetroban has Impacts on Tumor-Platelet Interactions and Tumor Growth

Thursday, October 24, 2024

10:00 AM - 11:00 AM EST

Location: Exhibit Hall E, F & G

Presenting Author(s)

Ann C. Rester

Undergraduate Research Assistant
University of Mississippi
Oxford, Mississippi, United States

Co-Author(s)

VT

Veeresh Toragall

Postdoctoral Research Associate
University of Mississippi, United States
PB

Parker Brewster, M.S. Engineering

Graduate Researcher
University of Mississippi
Oxford, Mississippi, United States

Primary Investigator(s)

Thomas A. Werfel

Associate Professor
University of Mississippi, United States

Introduction: Recent advancements in cancer research have highlighted the FDA-approved drug Ifetroban, previously utilized in cardiovascular contexts, as a potential treatment for preventing cancer metastasis. When tumor cells intravasate into blood vessels, activated platelets surround tumor cells, shielding these cells from immune surveillance and allowing them to migrate to secondary sites. Ifetroban functions by inhibiting the binding of Thromboxane A2 to thromboxane-prostanoid (TP) receptors on platelet membranes, thereby preventing platelet activation. Without the attachment of activated platelets to circulating tumor cells, the immune system should be able to detect and eliminate these cells before they establish secondary tumors. Previous in-vivo study findings suggest that Ifetroban may affect tumor metastasis and tumor growth. Hence, we hypothesize that Ifetroban may have anti-tumor potential (via direct or indirect modulations). Therefore, in the present study, we aim to investigate Ifetroban’s role in both tumor growth and platelet activation by using in-vitro assays, in-vivo models, as well as a microfluidic device designed to simulate physiological conditions. The findings of this study will provide crucial insights into Ifetroban's mechanisms in cancer treatment, particularly its potential as a safe and effective therapeutic option for inhibiting cancer metastasis and reducing tumor size.

Materials and

Methods: Cell viability studies were utilized for in-vitro experiments. First, various cell lines including MDA-MB-231, HEK-293, MCF-10A, and RAW 264.7 were seeded in a 96-well plate and allowed to reach confluency over 24 hours. Then, cells were treated with Ifetroban at varying concentrations and incubated for an additional 24 hours. Finally, cell viability was assessed using the CellTiter Glo luminescence assay. In the in-vivo studies, mice underwent a 2-week pre-treatment period of daily oral doses of Ifetroban (50 mg/kg body weight). Then, a tumor was induced in the mammary fat pads of the mice. After 24 days, the tumors were excised for size measurement and immunohistochemistry analysis. This analysis will be used to shed light on the mechanisms underlying Ifetroban’s impacts on tumor growth. For our microfluidic device assay, the device was designed using CAD software and 3-D printed using clear resin on a glass slide for imaging. While the specifics of the procedure for the device have not yet been finalized, our aim is to simulate the mechanical conditions of blood vessels and show the impact that mixing has on tumor-platelet interactions in comparison to static assays.

Results, Conclusions, and Discussions: In-vitro assay findings show that Ifetroban is not directly cytotoxic to any of the cell lines listed above, including the triple-negative breast cancer cell line MDA-MB-231. This indicates the need for further studies, such as cell growth assays, to determine the mechanism responsible for the observed reduction in tumor size in mice pre-treated with Ifetroban. In-vivo studies show a reduction in tumor volume and weight after two weeks of pre-treatment with Ifetroban. Immunohistochemistry results from these experiments will be available upon completion of slicing and staining of our samples. Upon return of these samples, we will analyze tumor morphology and assess primary biomarkers associated with angiogenesis, apoptosis, and cell proliferation (CD31, DNA TUNEL, and Ki-67, respectively). This will help inform the mechanism behind the reduction in tumor size. The development of our microfluidic device has been meticulously executed over several months. As we continue to optimize its design and procedure, our objective is to study platelet-tumor interactions in a more dynamic environment in comparison to previous static assays. Thus, it will allow us to study the tumor microenvironment in a way that more closely mimics physiological conditions.

Hence, we demonstrate that the anti-platelet activation drug Ifetroban may be a potential treatment for cancer metastasis by both targeting platelet activation and reducing tumor growth. Further work regarding platelet activation will determine the impact that mixing, achieved through the use of a microfluidic device, has on platelet-tumor interactions. Additionally, further work will determine the potential mechanism by which Ifetroban causes a reduction in tumor growth.

Acknowledgements (Optional): This work was supported by the Mississippi INBRE, funded by an Institutional Development Award (IDeA) from the National Institute of General Medical Sciences of the National Institutes of Health under grant number P20GM103476. Additional thanks to the Biomedical Engineering Department at the University of Mississippi, the interdisciplinary NanoBioSciences Lab (iNBS), and the NIEC core lab. Finally, I would like to thank Dr. Werfel and Dr. Toragall for their mentorship.